A former US National Security Agency officer says the 9/11 investigative author Philip Marshall and his children were killed in a “black ops hit” by the CIA, dismissing the suicide hypothesis.

Wayne Madsen said in a show organized by Kevin Barrett, a founder of The Muslim-Jewish-Christian Alliance, that he had reached the conclusion after a weeklong investigation.

Marshall was afraid of being silenced for his revelations about 9/11, Madsen said, noting that a side door the investigator never used was wide open when his dead body was found.

Along with Marshall, 14-year-old Micalia and her 17-year-old brother Alex were also found dead.

Madsen suggested that Marshall, who had observed many covert operations, had decided to shed light on mysterious issues in the last years of his life.

Marshall believed the former US President George Bush had pulled off the 9/11 attack to foment a government coup. In his fourth book, he was supposed to disclose blockbuster information.

According to Madsen, the crime scene was cleaned up by professionals, and there was also “an SUV, license plate undetermined, with an array of communication antennas bristling from the roof” outside the building.

In a recent interview with Press TV, Barrett said, “Of course, here in the US, where national security community we’re talking about could be both Israel and the US because essentially the US community has been taken over by the Israeli community since 9/11.”

“It seems that Philip Marshall had gotten his hands on some kind of explosive information as he [Madsen] put it. And, he was planning to publish this in his next book,” he added.

A pilot who wrote a conspiracy theory book about 9/11 is dead after he shot his two teenage children and family dog before turning the gun on himself.

Relatives and friends of Phillip Marshall were stunned by the violent crime which took place in Calaveras County on Saturday.

Their bodies were discovered when friends of the teens went to the family home on Sandalwood Drive and looked through the windows, they could see 54-year-old Phillip Marshall lying on the floor in a pool of blood.

Micalia Phillips, 14, and her 17-year-old brother Alex, were also found dead at the home inside the gated Forrest Meadows community.

Sheriff’s Sgt Chris Hewitt says when deputies arrived around 3pm on Saturday, they found the victims dead of apparent gunshot wounds in what they believe is a murder suicide.

Chimente is the principal of Bret Harte High School in nearby Angels Camp, where the two teens attended.

'Our first concern is not only reaching out to the family and giving them the support they need, but also supporting our students,' said Chimente.

Grief counselors were called in to help students deal with the sudden death of their friends and classmates.

A preliminary examination showed that all three were shot once in the head with a handgun.

Hewitt says the mother of the teens and estranged wife of Phillip Marshall, was out of the country at the time.

The former airline pilot's controversial conspiracy book The Big Bamboozle: 9/11 and the War on Terror was released last year.

While he was writing it, Marshall believed that his life was in danger because of the allegations involved.

According to Santa Barbara View, during the editing and pre-marketing process of Marshall’s book, he expressed some degree of paranoia because the nonfiction work accused the George W. Bush administration of being in cahoots with the Saudi intelligence community in training the hijackers who died in the planes used in the attacks.